SIGNIFICANT DIFFERENCES

A safe approach in any type of airplane culminates in a
particular position, speed, and height over the runway
threshold. That final flight condition is the target
window at which the entire approach aims. Propeller
powered airplanes are able to approach that target from
wider angles, greater speed differentials, and a larger
variety of glidepath angles. Jet airplanes are not as
responsive to power and course corrections, so the
final approach must be more stable, more deliberate,
more constant, in order to reach the window accurately.
The transitioning pilot must understand that, in spite
of their impressive performance capabilities, there are
six ways in which a jet airplane is worse than a piston
engine airplane in making an approach and in
correcting errors on the approach.

• The absence of the propeller slipstream in
producing immediate extra lift at constant
airspeed. There is no such thing as salvaging a
misjudged glidepath with a sudden burst of
immediately available power. Added lift can
only be achieved by accelerating the airframe.
Not only must the pilot wait for added power but
even when the engines do respond, added lift
will only be available when the airframe has
responded with speed.

• The absence of the propeller slipstream in
significantly lowering the power-on stall speed.
There is virtually no difference between power-on
and power-off stall speed. It is not possible in
a jet airplane to jam the thrust levers forward to
avoid a stall.

• Poor acceleration response in a jet engine from
low r.p.m. This characteristic requires that the
approach be flown in a high drag/high power
configuration so that sufficient power will be
available quickly if needed.

Figure 15-23.Typical approach and landing profile.